Jennifer Esposito isn't holding back—and it might just lead to a permanent departure from CBS' cop drama Blue Bloods, insiders tell us exclusively.

Shortly after CBS told Deadline that the 39-year-old actress—who has played Danny Wahlberg's partner Jackie Curatola for three seasons—would be taking a leave of absence, Esposito took to Twitter to put CBS on blast.

"CBS PUT me on unpaid leave an has blocked me from working anywhere else after my doctor said u needed a reduced schedule due to celiac," she wrote. "CBS didn't listen to my doc and I collapsed on set. Which everyone saw! After a week off, my doc said I could return to work but CBS implied that I was NOT truly ill and this was a scheme to get a raise! It's been almost two months without brining me back to work + keeping Me from working anywhere else!… Absolutely shameful behavior."

Insiders at CBS tell us that although the studio initially was hopeful Esposito would return at some point, that is "far less likely now" after her Twitter rant. Says one source: "The most likely scenario is that another actress will come in permanently to play Danny's partner." First up will be Megan Ketch, who has signed on for four episodes, and who could end up sticking around.

CBS tells us in a statement: "Jennifer has informed us that she is only available to work on a very limited part-time schedule. As a result, she's unable to perform the demands of her role and we regretfully had to put her character on a leave of absence. She is a wonderfully talented actress and we hope that she will be able to return at some point in the future."

The actress (and former Mrs. Bradley Cooper) has been vocal about her struggles with celiac disease, becoming an advocate to help others with the condition and launching the jennifersway website. She was diagnosed three years ago and also has been a regular on Blue Bloods for three seasons, after originally appearing as a guest star.